Railway track layout modelling and its application to an automatic route setting system
Computers in Railways XIV
Automatic Route Setting (ARS) is a major subsystem of railway traffic management systems. ARS automatically sets routes in accordance with timetables, train descriptions and facility situations. To develop the ARS system, various conditions have to be considered, such as train operations, track layouts, and equipped facilities. This leads to a huge amount of work in ARS development aimed at dealing with software variations among ARS products. In the software development area, model-based
... model-based development is commonly used to improve productivity. However, it requires a particular model for each system, and there is no applicable model for ARS. Thus, this paper proposes a new model that focuses on the topological relationships between two routes. In this model, railway tracks are expressed as a digraph in which a node and an edge respectively represent a route and a topological relationship between two routes. By analysing topological aspects of railway tracks, we found that edges are categorised into 23 patterns. Each is associated with a specific kind of routesetting feature. For example, a train has to choose an appropriate route where two routes diverge or wait until higher priority trains pass where two routes confluent. By using this model, the ARS system can be designed as follows. Trains move on the digraph and occupy nodes on their path in order to set routes. Each node and edge in the model is linked to specific route-setting functions. When a train tries to occupy a node on its path, ARS executes the functions linked to the node and its connecting edges to decide whether the train can occupy it or not. Some trial systems which have the same functions as existing ARS systems were developed for the feasibility study and were confirmed to ensure high productivity and customisability of the new ARS.